Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754526AbXJVU0n (ORCPT ); Mon, 22 Oct 2007 16:26:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751677AbXJVU0f (ORCPT ); Mon, 22 Oct 2007 16:26:35 -0400 Received: from iabervon.org ([66.92.72.58]:52630 "EHLO iabervon.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751408AbXJVU0e (ORCPT ); Mon, 22 Oct 2007 16:26:34 -0400 Date: Mon, 22 Oct 2007 16:26:32 -0400 (EDT) From: Daniel Barkalow To: Jeff Garzik cc: Linas Vepstas , Shane Huang , davem@davemloft.net, gregkh@suse.de, htejun@gmail.com, brice.goglin@gmail.com, david.gaarenstroom@gmail.com, linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, shane.huang@amd.com, linux-ide@vger.kernel.org, Brice Goglin Subject: Re: [patch] PCI: disable MSI on more ATI NorthBridges In-Reply-To: <471911BE.2000405@garzik.org> Message-ID: References: <20071019195749.GK29903@austin.ibm.com> <471911BE.2000405@garzik.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1877 Lines: 46 On Fri, 19 Oct 2007, Jeff Garzik wrote: > Linas Vepstas wrote: > > On Fri, Oct 19, 2007 at 09:17:23PM +0800, Shane Huang wrote: > > > Since we have little experience on PCI and MSI here, we had to try to > > > > As someone else pointed out, AMD should have *lots* of people with > > pci and msi experience on the payroll. (Folks here buy AMD-designed pci > > chips ...) > > > > > ONLY > > > comment out the pci_intx() call in drivers/ata/ahci.c > > > My system can boot up too with MSI enabled! > > > > > > So does it mean that the root cause is our SB700 SATA controller > > > has a hardware bug where setting INTX_DISABLE in the PCI COMMAND > > > register masks MSI interrupts too? > > > > That's what it sounds like, to me. > > > > > And what is the software solution or workaround? > > > > Not sure. Sounds like the device driver needs a quirk for this part. > > > Take a look at tg3.c net driver change > 2fbe43f6f631dd7ce19fb1499d6164a5bdb34568 which is a similar situation. > > However, it may turn out that removing the pci_intx() stuff as a general rule > is easier than quirking these devices, if enough of them turn out to have this > hardware bug. At a first approximation, ATI/AMD devices don't send any interrupts if intx is disabled, nVidia devices send legacy interrupts in addition to MSI ones if intx isn't disabled, and Intel devices actually work correctly. So we need at least one kind of device quirk for intx and msi. (And doing it in the drivers doesn't work, since everybody is making things driven by snd_hda_intel and would like msi, afaict) -Daniel *This .sig left intentionally blank* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/